DNA methylation is one of the most deeply-studied epigenetic mechanisms, DNA methylation plays an important role in the maintenance of normal function of cell, protection of the genomic integrity from the damage of parasitic DNA fragments, chromatin structure modification, X-chromosome inactivation, genomic imprinting, embryonic development and human tumorigenesis, and DNA methylation has become one of the most active research fields at present.
However, at present, methods for the detection of methylation in specified genomic regions, such as promoter regions, CpG island regions, CGI shore regions and imprinted gene regions, are still to be improved.